2.8 Summary The take-off data card was most likely completed using performance data from the BLT. The FDR data for the Halifax take-off was nearly identical to that of the Bradley take-off, indicating that the Bradley take-off weight was used to generate the performance data in Halifax. The Bradley weight in the weight and balance page was likely unknowingly transferred to the performance page due to a reversion feature of the software. The user subsequently selected calculate, which resulted in the generation of take-off performance data containing incorrect Vspeeds and thrust setting for Halifax. The flight crew used the incorrect Vspeeds and thrust setting during the take-off attempt; however, the settings were too low, especially the thrust setting, to enable the aircraft to take off safely. Factors that likely contributed to the incorrect take-off data being generated and then not being detected before the take-off attempt were flight crew fatigue, non-adherence to procedures, inadequate training on the BLT, and personal stresses. Once the take-off had commenced, the crew's situational awareness likely was not sufficient to allow them to detect the inadequate acceleration before it was too late to take off safely. Factors that likely contributed to this condition were flight crew fatigue and a dark take-off environment.